This proposal is in response to PA 00-019. My goal is to pursue a research career in an academic setting with a substantive focus on the etiology of adolescent psychopathology. In particular, I am interested in understanding the factors that promote substance use disorders (SUD), and the comorbid relationship that SUD has with other psychopathology. Although my past training has provided me with a foundation in conducting longitudinal studies of adolescent SUD, none of my prior training has been broadly focused on developmental psychopathology. The central aims of the proposed Research Career Award (RCA) will be to (1) provide advanced training in research methods and quantitative techniques necessary for me to continue developing as an independent investigator and (2) to conduct an investigation that will advance our understanding of the SUD and suicidality, particularly in an extremely high-risk population of homeless adolescents. The performance site will be the University of Washington at Seattle, and my training mentors will be Drs. Thompson, Baer, and Cauce locally, and Dr. Hops from the Oregon Research Institute in Eugene, OR. I would like to develop a unique understanding of comorbidity issues within the street youth and eventually expand my research into comorbidity issues with adolescents in general. Specific Aims of the study are: 1) Examine a specific set of variables that potentially lead to substance abuse or suicidality in homeless adolescents. This will be accomplished by empirically testing and validating a "risk amplification" model based upon a set of risk factors that are prevalent with homeless adolescents. 2) Second, we will examine whether drug involvement in homeless adolescents can be described in the same manner as it has for a high school sample of adolescents. Specifically, we will empirically test whether a multidimensional model of drug involvement developed to explicate the substance abuse of domiciled youth can be extrapolated to an extremely high-risk sample of street youth. I will also (1) continue my collaborative work with Drs. Thompson, Baer, Cauce, Hops on studies from their labs/research teams, (2) take courses in quantitative techniques, methodology, developmental psychopathology, and ethics, and (3) develop an R01 based upon the findings from this study.